refactor: import nixosModules unconditionally, add enable options

nixosModules/default.nix

@@ -0,0 +1,37 @@
+{ ... }:
+{
+  imports = [
+    # keep-sorted start
+    ./allowed-unfree-list.nix
+    ./amd-graphics.nix
+    ./autoupdate.nix
+    ./distributed-builds.nix
+    ./en-de.nix
+    ./extra-caches.nix
+    ./firmware-updates.nix
+    ./globalinstalls.nix
+    ./gnome.nix
+    ./intel-graphics.nix
+    ./kdeconnect.nix
+    ./latex.nix
+    ./lix-is-nix.nix
+    ./modern-desktop.nix
+    ./muede-desktop-settings.nix
+    ./nix-ld.nix
+    ./openssh.nix
+    ./podman.nix
+    ./printing.nix
+    ./prometheus-node.nix
+    ./pxvirt-guest.nix
+    ./quiet-boot.nix
+    ./secure-boot.nix
+    ./steam.nix
+    ./stylix.nix
+    ./systemd-boot.nix
+    ./tailscale.nix
+    ./user-muede.nix
+    ./user-ronja.nix
+    ./wine-gaming.nix
+    # keep-sorted end
+  ];
+}